Functionally inactive protein C inhibitor in seminal plasma may be associated with infertility
Functionally inactive protein C inhibitor in seminal plasma may be associated with infertility
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DOI：
10.1093/molehr/5.6.513
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发表时间：
1999-06-01
影响因子：
4
通讯作者：
Liu, YX
中科院分区：
文献类型：
--
作者：
He, SP;Lin, YL;Liu, YX
精浆中发现了蛋白C抑制物(PCI)，被认为可以保护完整的周围细胞和精浆蛋白免受蛋白水解性损伤。在本研究中，我们发现两例不育患者精浆中的PCI抗原水平正常或略有升高，但对尿激酶型纤溶酶原激活物(UPA)和组织型纤溶酶原激活物(TPA)缺乏抑制活性。相反，这两个样本的uPA和tPA蛋白水解酶活性是正常志愿者的20-60倍。对pCI-uPA复合体形成的时间过程分析表明，在肝素存在下，正常精浆在15分钟内形成了80%的复合体，而在150分钟孵育后形成了整个复合体，而在两个患者样本的检测中，没有观察到对肝素刺激的反应。同样，在正常精浆中肝素刺激30分钟后，90%的pCI-tPA复合体形成，但在两个患者样本中没有观察到反应。在活化蛋白C(APC)存在下的PCI抑制功能的动力学分析表明，这两例患者的PCI抑制活性缺失，且不受肝素的刺激。Western blotting还显示，在正常样本中，大多数完整的PCI分子与uPA或tPA形成了复合体，但在两个患者中的一个样本中没有形成复合体，在另一个样本中观察到的复合体很少，这表明两个患者样本中的PCI是不活跃的。这些结果提示，精浆中功能不活跃的PCI值可能与不育症有关。
Protein C inhibitor (PCI) has been found in seminal plasma and is considered to protect intact surrounding cells and seminal plasma proteins from possible proteolytic damage. In the present study, we showed that although the antigenic levels of PCI in two seminal plasma samples from patients with infertility were normal or slightly elevated, their inhibitory activities toward urokinase plasminogen activator (uPA) and tissue-type plasminogen activator (tPA) were absent. In contrast, uPA and tPA proteolytic activities in these two samples were 20-60-fold higher than that from normal volunteers. A time-course analysis of PCI-uPA complex formation showed that >80% of the complex had been formed within 15 min in normal seminal plasma in the presence of heparin, compared with the total complex formed after 150 min incubation, whereas no response to heparin stimulation was observed in the assays with the two patient samples. Similarly, >90% of PCI-tPA complex was formed after 30 min of heparin stimulation in normal seminal plasma but no response was observed in the two patient samples. Kinetic assays of PCI inhibitory function in the presence of activated protein C (APC) showed that PCI inhibitory activity in the two patient samples was absent and not stimulated by heparin. Western blotting also showed that most of the intact PCI molecules, in normal samples, formed complexes with either uPA or tPA but there was no complex formed in one of the two patient samples and very little complex was observed in the other, suggesting that PCI in the two patient samples is inactive. These results suggest that the presence of functionally inactive PCI in seminal plasma may be associated with infertility.